CELLULOSE ACETATE PHTHALATE (C-A-P)

Cellacefate USP / NF, EP, JP

C-A-P is a cellulose in which about half the hydroxyl groups are acetylated, and about a quarter are esterified with one of two acid groups being phthalic acid, where the remaining acid group is free. It is a pH-sensitive cellulose derivative designed for enteric coating of pharmaceutical dosage forms like tablets or granules. It can also be used for matrix drug delivery.

C-A-P can withstand prolonged contact with acidic gastric fluids while being able to dissolve readily in the mildly acidic to neutral environment of the small intestine. C-A-P is commonly applied to solid-dosage forms either by coating from organic or aqueous solvent systems or by direct compression. C-A-P is compatible with many plasticizers and the addition of plasticizers improves the water resistance of this coating material thus making the formulations more effective.